Filtering material.



UNITED STATES."

PATENT orrron.

,O'SWALD LOF LER AND WILHELM wEIDLnoF VIENNA, AUSTRIA= HUNGARY.. v

FILTERING MATERIAL}.

Specification ofLetters Pea-a.

Patented March 20, 1906.

' Application filed mm, 1905. serin'ra'zszsoi. Y

To all whom it may concern; Be it known that we, OSWALD LoFFLER, a

' subject of, the Emperor of Austria-Hungary,

and W ILHELM, W EIDLE, a subject of the German Emperor, manufacturers, residing S11v1- enna, in the province of LowerAustria and Empire of Austria-Hungary, have invented.

new and .useful Improvements in a Filtering Material, of which the'following is a specification. -l

l The present invention relates to a filtering Imaterial consisting of'asbestos, chalk,fossilmeal, and syenite, these materials in a ver finely pulverized condition being mixedwit water to form amassor pastewhich is pressed intomolds and burned.

It is not new to obtain a filtering material by molding and burning a mixture of fossilmeal and asbestos to which organic substances are sometimes added but thematerial 'so obtained has certain disadvantagesfor instance, it breaks easil by shock or impact andhasnot sufficient so idity. Consequently it is quickly worn by friction and is therefore It even too rapidly worn out by cleaning. I dusts or crumbles when in a dry state. Moreover, capillary cracks and holes, through which the bacteria may pass into the interior of the filtering subs'tancejcannot be abso-- lutely prevented and permit of a rapid growing or passing through of the germs. Further, the use of syemte for the manufacture of filtering materials is also already known,

finelypulverized syenite alone moistened with water being pressed; into molds and burned. a The manufacture of such filtering materials is, however, very difficult, since the degree of pulvcrization, the'strength. of

compression, and the-temperature of'burning' must be in an exactly-definm'l proportion.

with the known filtering materials.

The filtering material. produced according to the present invention has none of the com letely prevented, and therefore the ens ul ing isadvantages.

with most filtering materials, whereas with the known filtering materials a quantity of Cracking does'not result even when sterilizing, which usually happens bacteria, although a very small proportion thereof pass t'hrou h the filtering material, a number of tests with the improved filtering material have resulted in a product abso- This filtering matelutely free from germs. I rial has also an invariable hardness combined with great toughness so that it is not affected by external influences, such as shocks, 'impacts, or falls. j 1 Having now described our invention, what we claim, and desire to secure by Letters Patentpf the United States, is-

.A filtering material consisting of finely-pulverized asbestos, chalk,- fossil-meal and syenite mixed with water, the mixture being pressed into molds and burned In testimony whereof we have signed our names tothis specification in the presence of two subscribing witnesses.

OSWALD LOFFLER.

Witnesses: HANS PAPPENHEIM, ALvEsTo S. HoG E.

WILHELM WEIDLE. A 

